Flat-panel display devices, such as an organic electroluminescence (EL) display device and a liquid crystal display device, have been used in various fields. In recent years, as regards mobile information terminal devices such as mobile phones and PDAs (personal digital assistants), there has been an increasing demand for a display device having a less thickness and a less weight. For example, as a method of realizing a less thickness and less weight, there is a technique wherein a glass substrate is replaced with a resin layer of, e.g. polyimide with a relatively high heat resistance, and the resin layer is formed on a glass substrate. After TFTs, etc. are formed on the resin layer, the resultant structure is divided into cells, and the resin layer is finally peeled from the glass substrate. Thus, a sheet display is manufactured.
In this process, however, when many panels are assembled batchwise by using mother glass substrates and then the assembled body is separated into individual panels, it is necessary to cut the resin layer together with both attached mother glass substrates, and this makes it difficult to take out electrodes for mounting signal supply sources which are necessary for displaying images on the panels. This being the case, there has been a demand for an improvement in productivity.